Wafer-level chip scale package (WLCSP for short) is commonly used in MEMS (micro-electro-mechanical-system) industry. Since the WLCSP does not require lead frame and wire bonding, its associated packaging cost becomes very attractive. Especially in the field of consumer electronics, MEMS-based WLCSP products will replace the traditionally packaged sensors. There is a need for high throughput and accurate final testing for MEMS wafer-level chip scale packaging products.
However, to achieve high throughput testing, packaged sensors are placed individually in either complex and expensive carriers or test socket boards and testing is performed in parallel. Handling individual packaged sensors by pick and place machine causes package jam and thus produces yield loss. Furthermore, positioning differences between packages lead to low repeatability and stimulus inaccuracy.
Therefore, there is a need to provide an improved method for wafer-level chip scale package testing to overcome the above mentioned problems.